Method of and device for operating luminous tubes



z. BAY 1,936,005

METHOD OF AND DEVICE FOR OPERATING LU'MINOUS TUBES Nov 221 21933.

Filed Oct. I 25, 1929 IIIIHH' 7mm mmmq EVE/Won Patented Nov. 219193;

PATENT OFFIC 1,930,005. a AND navrcs roa or'ala'rma 1 wumous'roass- A} Zolton Bay, Berlin,,Germuiy and iii-Hungary October 2, 1m

' Application ctober23, 1929, Serial No. i

9 Claims. (01. 176-124) I This invention relates, flrstly, to a method of operating luminous tubes, and secondly, to means for use in connection with that method. Electric discharges in attenuated gases are, as is 6 lmown, accompaniedbyluminous efiects, the color of which is determined by the pressure and the kind of the respective gas. Luminous tubes of this kind require a certain minimum strength ofthe electric current in order to be able to produce a practically useful luminous effect. The radiationarising at this. minimum of current will hereinafter be termed fundamental radiation andthe corresponding color will be termed fundamental .color.

The object of the present invention is to act upon the fundamental colors of luminous tubes having a certain distinct or definite gas filling, and for this object, i. e. for the purpose of varying or changing the respective fundamental color, the respective tube is subjected to the action of current impulses which are separated .from one another by distinct time intervals, the duration of each of which is a multiple of that of each individual impulse the intensity or strength of the impulses being several times the effective strength of the respective current.

The manner of action, and the effect of this operation, can be explained and understood with the aid of the following considerations:

The molecules or the atoms of the attenuated gas filling, when being excited by the electric charge, produce a large number of different intermediate products. Thus, forinstance, a tube filled with hydrogen, when being excited, besides the normal biatomic neutral hydrogen molecules, also generates hydrogen molecules with positive charge, neutral atoms, excited atoms, and even triatomic molecules, and the like. These different intermediate products can be rendered luminous by electronic impacts. The colors of the luminosities emitted by the various intermediate products are different.

The effect. attained by, and according to, this invention, is based upon the feature that at will one or another or any one of the intermediate products is rendered luminous. It appears that the frequency of the electronic impacts is the determining factor, an assertion, which can be substantiated as follows:

The intermediate products generated by theexcitation of the tube have a certain definite finite lifetime; they are, thus, continually generated and continually annihilated, and their constant concentration is determined by the fact that the generation process and the annihilation process are in equilibrium with one another.

Inordertoexcitethe spectrumofanintermediatetransitorysuhstaneeitisnecessarythatits corpuscles be excited by electronic impacts imi mediate]! after the! av ee produced. a d

- tronic impacts.

withintheirlifetime. Inthiscasetheintensityof the spectrum of an intermediate product re-' veals itself in a twofold dependency upon the strength of the current, as follows:

(1) The concentration of the intermediate product in the gas space, that is to say. the percentage of the amount of the intermediate product in proportion to the entire amount of the gas, is a function of the strength of the current, and the concentration, in general, increases with the strength of the current.

(2) The probability of the excitation of the corpuscles of an intermediate product to radiation is a function of the frequency of the elec- This frequency also rises with the strength of the current. a

It follows therefrom that the proportion of the intensities of the various spectra generated in a tube and, thus, the color of the emitted light, is, with a given gas or vapor content, determined by the strength of the current. Therefore, the color 1 of the emitted light can be varied during operation by varying the strength of the current. The luminous tube requires, as has already been mentioned, a certain minimum strength of current to produce a useful luminous effect. The radiation arising at this minimum strength of current had been termed fundamental radiation" in the introductory part of this specification, and the radiation attained by an increase of the strength oi. current will now be termed "forced" radiation.

Now, in order to change per'ceptibly the color of the radiated light at said minimum current strength, this lattermust be increased to several times the original value. By way of example I mention that a certain luminous tube containing a neon-mercury filling emits a blue. light at the normal load of about 100 milliamperes. To attain the first forced radiation at which the tube emits a red-yellow light, the strength of hundredfold.

The load of a tube cannot, however, be increased materially beyond the normal load without heating the tube toa detrimental or destrucno tive degree, but as, according to this invention, the tube is fed with a series of current impulses, the maximum strength of which is several times that of the effective strength .of' the current,

the high strengths of current requisite for the excitation of the forced radiation can be attained without overloading the luminous tube. with a sinusoidal alternating current the m :imum strength of the current is the ,li-zomv of the elective strength of the current, whereas,

ing on which Figs. '1-4 are diagrams added in order to make the invention clearer. In Figure 1 I denotes the sinusoidal curve of the strength of an alternating current which is to have the effective strength J1 in order to be able to produce a practically useful luminous eflect in a tube of given size without exceeding the admissible load, it being assumed that the tube emits the fundamental radiation.

If, in order to produce the forced radiation, current impulses II, IL'lI are employed, a maximum strength of current Jmaa: can be attained which is manyfold, about the tenfold up to several, hundredfold, of the effective strength of current J: which corresponds to the proper load of the luminous tube.

It is immaterial whether or not this efiectlve strength of current J: is equal to J1. The strength of current J: may be greater, but not by so much that the tube is overloaded, or it may be smaller,

but not by so much that the intensity of the light is impaired.

Although it'is satisfactory for the p p se in view to have the impulses II II follow one another at regular intervals, still, this is not-indispensably requisite, provided, the frequency of the impulses be sufiicient to prevent apparent flicker or scintillation of the light. This requirement being observed, the frequency of the current impulses employed to produce the impressed radiation may be any desired one without influencing perceptibly the color of the light. Also the temporal course of the current curve may be as desired, as shown in the examples Figs. 2-4, provided, the requirements stated be fulfilled.

With the impulses of the current serving to I feed the luminous tubes the point to be observed is, therefore that their duration is only a small fraction, normally less than a tenth, of the time in which the impulses follow one another, so that after every impulse an interruption takes place,

the duration of which is about tenfold of the preceding impulse. Inasmuch as. the maximum strength of current is the determining factor for the generation of the light, whereas for the load of the tube the effective or the mean strength is the determining one, the possibility is afforded of producing the excitation of the gas or vapor therein by a current of any desired instantaneous value without an inadmissible increase of the load of the tube. In other words: the energy integral of the current impulses per unit of time must be approximately equal to the watt consumption in normal service with continuous current or with commercial alternating current.

By suitably choosing the ratio between the maximum and the effective strength of the current it is, in view of the large number of radiations rendered possible by the various intermediate transitory products, also made possible, to cause the gas or vapor to radiate in just the desired color, viz. either solely with the fundamental radiation or with a forced radiation of a higher or a lower order. The invention presents,

thus, a means for influencing the color of the emitted light, but besides making it possible to produce in luminous tubes, colors which heretofore have not been produced therein, it also affords the possibility of changing or varying the color during operation, by varying the ratio between the maximum strength and the effective strength of the current feeding the tube, or the shape of the current impulse curve respectively, during operation. That can be eflected either in -steps or gradually, so that the changes in, or

variations of, the colors also take place either in steps or gradually.

' The succession of current impulses can be produced in very different manners. Chiefly three methods-are used for the purpose in view, viz. firstly, production of the current impulses by discharging a condenser, secondly, producing said impulses electrodynamically, and thirdly, producing them with the aid of electronic tubes.

In the first of these methods a condenser is charged up to the disruptive voltage of a spark gap, and is then caused to discharge instantaneously through the luminous tube. This method can be carried out with variousarrangements and combinations of parts, as shown in Figs. 5-11. In Fig. 5 the charging voltage of a condenser 2 connected in parallel with the tube 1 is varied by varying the disruptive voltage of-a quenched spark gap inserted in series with the tube, this variation entailing a corresponding variation of the maximum intensity of the current impulse.

In Fig. 6 a variable resistance 4 is inserted into the discharge circuit of the condenser 2 connected in parallel with the tube 1, as in Fig. 5, the effect being that the duration of the current impulse is varied; In Fig. '7 a regulable self-induction coil 5 is inserted into the condenser discharge circuit of Fig. 5, said coil constituting an impedance which is variable while the current impulse proceeds through \its path, in that the quickly variable curve parts are choked by said coil more than are the less rapidly variable curve parts. In Fig. 8 another condenser 6 is connected in parallel with the tube 1 of Fig. 5, the effectof this arrangement being that the quick variations of the intensity of the current are shortcircuitd or passed by said condenser. In Fig. 9 a variable condenser 7 is inserted into the discharge circuit shown in Fig. 5 and is connected in series with the tube 1, the efiect being that the slower variations of the current impulse are suppressed.

Concerning Fig. 6 I may add that instead of a variable ohmic resistance 4 a capacitive resistance or an inductive resistance or a combination of such resistances may be used.

In Figure 10 the essential elements of the arrangements and combinations of parts shown in Figs. 5-9 are combined and united in one wiring diagram in which 5 denotes the variable. selfinduction coil, 9 a capacity in the discharge circuit of the condenser 2, and 11 a second condenser connected in parallel with the tube. In all figures (5-10) 10 denotes the charging transformer.

When feeding tubes with the various current impulses-mentioned care must be taken that the Figure 11 whereby the individual impulses follow one another in different intervals of time. That resistance is shown also in Fig. 10.

The second method mentioned can be carried out by means of rotatory electromagnetic current generators, for instance homopolar machines, which may be designed similar to those used for the production of the igniting sparks in internal combustion motors. The current impulses obtained by generators of these designs are approximately of the kinds shown in Figs. 1-4.

The third method mentioned can be carried out with the aidof an electronic tube, into the anode circuit of which the luminous tube is inserted, and the grid voltage of which is so controlled that the anode current attains the desired form in which it appears as a succession of current impulses.

I claim:

1. The method of producing in a luminous tube during operation thereof colors, tinges or hues other than the fundamental color of the same, said method consisting in subjecting the tube to the action of current impulses. separated from one another by intervals, the lengths of which are much greater than of the duration of every impulse, the intensity of the impulses being many times the effective strength of the current.

2. The method of producing in a luminous tube during operation thereof colors, tinges or hues,

, said method consisting in subjecting the tube to r Av the action of current impulses separated from current impulses separated from one another byv intervals, the lengths of which are much greater than the duration of every impulse, the intensity of the impulses being many times the effective strength of the current, and the current impulse curve being varied during operation.

4. The method of producing in a luminous tube during operation colors, tinges or hues other than the fundamental color of the same, said method consisting in subjecting the tube to the action of current impulses separated from one another by intervals, the lengths of which are much greater than the duration of every impulse, the intensity of the impulses being many times the eflective strength of the current, the watt consumption being approximately the same during the operation of the tube in diflerent colors with an alternating current of sine wave type in the fundamental color or with current impulses of diilerent maximum intensity and curve form for the modified colors.

5. The method of producing in a luminous tube during operation colors, tinges or hues other than the fundamental color of the same, said-method consisting in subjecting the tube to the action of current impulses separated from one another. by intervals, the lengths of which are much greater than the duration of every impulse, the intensity of the impulses being many times the efiective strength of the current, the current impulses being generated electromagnetically.

6. The method of producing inluminous tubes during operation colors, tinges or hues other than the fundamental color of the same, said method consisting in subjecting the tube to the action of current impulses separated from one another by intervals, the lengths of which are-much great.- er than the duration of every impulse, the intensity of the impulses being many times the efiective strength of the current, the current impulses being generated electromagnetically in the manner used in high tension magnetos for the production of the igniting sparks in internal combustion motors.

'7. An arrangement and combination of parts for producing in a luminous tube during operation colors, tinges or hues other than the fundamental color of the tube,- said arrangement and combination comprising, in connection with the luminous tube, a condenser charged in known manner; a discharge circuit pertaining to said condenser and having said tube inserted into it, and a quenched spark gap, the disruptive voltage of which is variable and which is also inserted into said circuit, and which is adapted to permit feeding the said. tube with successive current impulses, the intensity of which is variable.

8. An arrangement and combination of parts 1 10 for producing in a luminous tube during operation colors, tinges or hues other than the fundamental color of the tube, said arrangement and combination comprising, in connection with the luminous tube, a condenser charged in known manner; a discharge circuit pertaining to said condenser and having said tube inserted into it;

a quenched spark gap, the disruptive voltage of which is variable and which is also inserted into said circuit, and which is adapted to permit feed- 12 ing the said tube with successive current impulses,

the intensity of which is variable, and a resistance likewise inserted into the said circuit.

9. An arrangement and combination of parts for producing in a luminous tube during operation colors, tinges or hues other than the fundamental color 01' the tube, said arrangement and combination comprising, in connection with the luminous tube, 'acondenser, charged in known manner; a discharge circuit pertaining to said 13) condenser and having said tube inserted into it;

a quenched spark gap, the disruptive voltage of which is variable and which is also inserted into said circuit, and which is adapted to permit feeding the said tube with successive current impulses, the intensity of which is variable, and a resistance likewise inserted into the said circuit, and another condenser connected in parallel with V the said tube.

ZOLTAN BAY. 

